Such a method is known from JP2006337641. This Japanese document relates to a method for producing prisms having high angular accuracy wherein a laminated glass is obtained by bonding small and large substrates orderly. Subsequently, the glass laminate is cut into several pieces and double side polishing is carried out, wherein the cut glass pieces are divided into short strips by cutting at intervals more than the length of prism in orthogonal to the polishing surface. The short strips are polished along the cut surface with respect to the reference plane and strips are again cut at equal spacing in orthogonal to the polishing surface of double side polishing or short strip polishing.
JP 2010-122576 relates to a method for manufacturing an optical element having at least one optical thin film having a predetermined optical function inside the element, wherein the method includes a laminate joined body-forming step of laminating a plurality of sheets of parallel planar optical components so that the optical thin film and an adhesive are interposed between the components to form a laminate joined body.
WO2013049948 relates to a method for manufacturing an optical element, comprising the steps of providing a wafer comprising a multitude of semi-finished objects, separating said wafer into parts referred to as sub-wafers comprising a plurality of said semi-finished objects, processing at least a portion of said plurality of semi-finished objects by subjecting said at least one sub-wafer to at least one processing step. The wafer according to WO2013049948 comprises a multitude of semi-finished products obtained involving carrying out, e.g., one or more of lithographic processes, replication processes, coating processes, mechanical processes, etching processes, polishing processes and/or others. The wafer is divided into sub-wafers, e.g., by punching, sawing, cutting, or laser cutting, a sub-wafer comprising one or more, usually a plurality of said semi finished products. Then the sub-wafers are processed, wherein the processing may comprise one or more of lithographic processes, replication processes, coating processes, mechanical processes, etching processes, polishing processes and/or others. Then, the processed one or more sub-wafers are separated into a multitude of objects. The so-obtained objects may be used as obtained or may be subjected to further processing, e.g., to a packaging process or to a mounting process in which the object is mounted to another element or device.
JP 2003-137615 relates to a method for manufacturing optical devices, such as beam splitters, wherein two glass plates having a prescribed thickness, length and width are joined via an adhesive to form a plate laminate and this plate laminate is cut parallel to one lateral face in a prescribed width in such a way as to make bottom faces nearly square to form a plurality of blocks to be polished in a prescribed length, wherein joint surfaces extend parallel nearly at the centers. The four corners of each of the blocks to be polished are polished in such a way that the joint surface becomes a diagonal line of the square bottom face to form a regular quadratic prism-shaped device continuum. In a first step of the polishing, the polished block, as the diagonal of the square end surface is vertical, is attached to the first polishing jig and polished, and in a second step the first intermediate polishing block thus obtained is rotated 90° and attached to the first polishing jig again. In a third step the second intermediate polishing block thus obtained is rotated 90° and mounted on a second polishing jig and polished for obtaining the third intermediate polishing block. In the final step of polishing the third intermediate polishing block is rotated 90°, mounted on a third polishing jig and polished. The device continuum formed by this polishing process is cut at predetermined intervals by a cutting device, such as a cutter, and is a beam splitter.
US 2010/085466 relates to a method for manufacturing an image pickup unit comprising: a step of bonding plural lens wafers, on which optical components are formed, and forming a lens unit wafer including plural lens units; a step of bonding a bending optical element wafer including plural bending optical elements to a first surface of the lens unit wafer such that the plural bending optical elements are respectively opposed to the plural lens units and forming an optical unit wafer; a step of bonding a sensor wafer including plural solid-state image pickup devices to a second surface opposed to the first surface of the lens unit wafer in the optical unit wafer such that the plural solid-state image pickup devices are respectively opposed to the plural lens units and forming an image pickup unit wafer; and a step of separating and individualizing the image pickup unit wafer for each of the lens units, the bending optical elements, and the solid-state image pickup devices and manufacturing plural image pickup units. This US patent application teaches to manufacture plural optical units by bonding the plural lens wafers, on which the optical components are formed, and forming the lens unit wafer including the plural lens unit, bonding the bending optical element wafer including the plural bending optical elements to the first surface of the lens unit wafer and forming the optical unit wafer, and individualizing the optical unit wafer. The bending optical element includes, for example, a prism and is provided by bonding the emission surface to an outer surface of a flat plate serving as the first surface of a lens unit. A bending optical element wafer including a plurality of such bending optical elements is bonded to the first surface forming an incident surface of the light beam of a lens unit wafer, specifically, an outer surface of the lens wafer such that the bending optical elements are respectively opposed to the lens units and emission surfaces of the bending optical elements are set in contact with the lens units, and an optical unit wafer including a plurality of the optical units is formed.
US 2003/090753 relates an optical system such as a viewing or image pickup optical system that is used with an image display device or the like which may be mounted over the head or face of an observer or added to cellar phones or easy-to-carry information terminals.
U.S. Pat. No. 4,128,321 relates to a single lens reflex camera having a pentagonal prism.
Many mobile devices, such as mobile phones and tablet computing devices include cameras that may be operated by a user to capture still and/or video images. Because the mobile devices are typically designed to be relatively small, it can be important to design the cameras or imaging systems to be as thin as possible in order to maintain a low-profile mobile device. In various conventional devices, the thickness of the mobile device is maintained as small as possible by turning either the image sensor or the lens group on its side and using reflective devices to bend the rays to the sensor. It is also possible to maintain the thickness of the mobile device as small as possible by shortening the focal length of the imaging system.
An object of the present invention is to provide a method for manufacturing optical modules, in which optical modules the total track length is reduced to a minimum.
Another object of the present invention is to provide a method for manufacturing optical modules, wherein the thickness of the optical modules is maintained as small as possible by shortening the focal length of the imaging system without deteriorating its optical performances.